Simulation study on a new method for measuring capacitive current in distribution lines

The distribution network in China usually operates with ungrounded neutral points. Installing suitable arc suppression coils on distribution lines can effectively control the range of influence of single-phase grounding faults. To configure arc suppression coils with reasonable compensation capacity, accurate measurement of the distribution line is necessary. However, current capacitance current measurement methods often do not consider the impact of zero sequence voltage on the measurement results. This article proposes a new method for measuring capacitive current. Optimized the wiring method of traditional signal injection method. A line to ground capacitance analysis model considering the zero sequence voltage of the power grid was constructed. By injecting multiple sets of abnormal frequency signals into the open triangular end of the voltage transformer, the capacitance of the line to ground can be effectively measured and analyzed. The method in this article does not require measurement of the system phase angle, and the required instruments and equipment are simple and convenient for on-site operation. This new type of abnormal frequency signal injection method has guiding significance for the prevention and control of single-phase grounding faults in distribution lines.